Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

A Guide to the Mosquitoes (Diptera: Culicidae) of the Yukon

Daniel AH Peach1*, Sean McCann1, and Peter Belton1

1Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada

* Corresponding author: [email protected]

Abstract Mosquitoes (Diptera: Culicidae) are highly diverse, with over 3500 extant species worldwide. At least 33 species occur in the Yukon Territory. Correct identification of mosquitoes, as well as knowledge of their ecology, natural history, blood-feeding preferences, and ability to vector pathogens are essential for effective control measures and mosquito research. The Yukon is home to unending hordes of mosquitoes, and here we provide a comprehensive guide to their identification and biology. This guide may be of interest to students of Yukon natural history, mosquito-borne diseases, and wetland ecology, as well as mosquito control professionals, and is formatted for convenient printing and use.

Published online February 01, 2021

Introduction updated list of mosquitoes known from the Yukon, The Yukon Territory is home to a variety of different bringing together the scattered literature on all 33 species eco-districts, from towering mountains and moist Pacific known from that territory. We also provide keys to the Maritime conditions in the southwest to coastal plains adult females of Yukon mosquitoes, including those of and Arctic conditions in the north (Smith et al., 2004 an additional 5 species that are expected to occur there. ). Mean annual temperatures are below freezing, with While many of the mosquito-borne viruses found mean winter temperatures of around -20 oC and mean in southern Canada have not been reported from the temperatures during July, the warmest month, of 10-15 Yukon, there are two endemic arboviruses vectored by oC (Oswald and Jenyk, 1977). However, The Yukon is mosquitoes: snowshoe hare virus (SSHV) and Northway a land of extremes. Daily temperature fluctuations of 30 virus (NORV). SSHV is an Orthobunyavirus of the oC are not uncommon (Smith et al. 2004) and the lowest California encephalitis virus (CEV) serogroup primarily recorded temperature in North America, -63 oC, is from found in snowshoe hares (Lepus americanus) and arctic the Territory (Thomson 1958). The Yukon Territory is ground squirrels (Citellus undulatus) (McLean et al., also home to seemingly unending hordes of mosquitoes. 1972). Aedes communis is thought to be the primary Some of these belong to species that are widespread and vector of SSHV, though Ae. nigripes, Ae. hexodontus, abundant, easily surviving cold winters and thriving and Cs. inornata may also be vectors, and the virus has during brief summer conditions, while others are found in been isolated from a variety of other species (McLean low numbers only in certain habitats, at the very northern et al., 1972, 1974; Ritter & Feltz, 1974; McLean & margin of their distribution. In the last review of the Lester, 1984). SSHV can infect humans and livestock mosquitoes of the Yukon (Belton & Belton, 1990) a total and while clinical cases are rare, they do occur (Heath of 28 species were known to have been recorded from et al., 1989; Meier-Stephenson et al., 2007; Goff et al., the Territory, with an additional 4 species that probably 2012; Lau et al., 2017). NORV was originally isolated occur there. Since this review two additional territorial from mosquitoes in Alaska (Ritter & Feltz, 1974) and has records have been made and three of the species that since been found in the Yukon and Northwest Territories were thought to exist in the Yukon have been confirmed (McLean et al., 1977, McLean et al., 1979a, McLean (Peach 2017, 2018; Peach and Poirier 2020). Changes et al. 1979b). Antibodies for NORV have been found in the distribution records of several species in British in humans and large ungulates (Walters et al., 1999), Columbia indicate that there may be additional species in but no clinical infections have been reported. Western the territory that should be considered when identifying equine encephalitis virus (WEEV) and eastern equine specimens. The purpose of this paper is to provide an encephalitis (EEEV) have not been reported from the

The Canadian Journal of Arthropod Identification is a product of the Biological Survey of Canada and the Entomological Society of Canada.

doi:10.3752/cjai.2021.43 1 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Yukon (McLean et al., 1974; Artsob, 1990), though accessible locations, often close to population centres. Burton & McLintock (1970) did find serum neutralizing There is a dearth of information on the bionomics of antibodies for WEEV in caribou (Rangifer tarandus) in Yukon mosquitoes, and western and northern mosquitoes the Northwest Territories. West Nile virus (WNV) and St. in general. We have had to rely on information from a Louis encephalitis virus (SLEV) have both been detected variety of other areas to provide a background on some of in migratory birds in Alaska (Pedersen et al., 2016), and the species in this guide. While information from adjacent may similarly be present in the Yukon. While mosquito areas such as Alaska or Northern British Columbia is transmission of these pathogens seems unlikely due to likely comparable, much information comes from much the short duration of the growing season, with respect to farther afield and one should be aware this may not be WNV some climate models predict increasing prevalence reflective of western/northern populations of even the in adjacent areas (Chen et al., 2012) which may also same species. indicate increased risk in the Yukon. Nomenclature used here follows Wilkerson et al. Most of the records in the Yukon are the results of (2015) with respect to generic names within the tribe collecting in the early to mid 20th century (Dyar, 1919, Aedini, and subgeneric names are included to show the 1920, 1921; Freeman, 1952; Curtis, 1953), with some earlier name changes found in Darsie & Ward (2005). sporadic efforts made up to the late 20th century (Nelson We also follow Darsie & Ward (2005) in considering 1977; Wood et al. 1979; McLean et al. 1981; McLean & Aedes (Ochlerotatus) idahoensis a subspecies of Aedes Lester 1984; Wood 1989 pers. comm. in Belton & Belton (Ochlerotatus) spencerii. 1990). However, there is not just a paucity of collecting For additional information see guides to all Canadian records but also unevenness in their distribution. Outside mosquito species by Wood et al. (1979) and Thielman and of the main transportation corridors most of the Yukon is Hunter (2007), to the mosquitoes of British Columbia by inaccessible other than on foot, by canoe, or by air, and Belton (1983), to the mosquitoes of Alaska by Gjullin et many of the areas that can be reached by automobile are al. (1961), and to the mosquitoes of North America, north only accessible on rough, pitted gravel roads. Due to this of Mexico, by Darsie & Ward (2005). lack of access most collecting has been done from easily-

Table 1: Checklist of mosquitoes of the Yukon. †Unrecorded but expected to occur in the Yukon.

Aedes (Aedes) cinereus Meigen Aedes (Ochlerotatus) nigripes (Zetterstedt) Aedes (Aedimorphus) vexans (Meigen) Aedes (Ochlerotatus) nigromaculis (Ludlow)† Aedes (Ochlerotatus) campestris Dyar and Knab Aedes (Ochlerotatus) pionips Dyar Aedes (Ochlerotatus) canadensis (Theobald) Aedes (Ochlerotatus) provocans (Walker)† Aedes (Ochlerotatus) cataphylla Dyar Aedes (Ochlerotatus) pullatus (Coquillett) Aedes (Ochlerotatus) aboriginis Dyar† Aedes (Ochlerotatus) punctor (Kirby) Aedes (Ochlerotatus) churchillensis Ellis and Brust† Aedes (Ochlerotatus) riparius Dyar and Knab Aedes (Ochlerotatus) communis (de Geer) Aedes (Ochlerotatus) spencerii ssp. spencerii (Theobald) Aedes (Ochlerotatus) decticus Howard, Dyar, and Knab Aedes (Ochlerotatus) sticticus (Meigen) Aedes (Ochlerotatus) diantaeus Howard, Dyar, and Knab Aedes (Ochlerotatus) ventrovittis Dyar† Aedes (Ochlerotatus) euedes Howard, Dyar, and Knab Anopheles (Anopheles) earlei Vargas Aedes (Ochlerotatus) excrucians (Walker) Coquillettidia (Coquillettidia) perturbans (Walker) Aedes (Ochlerotatus) fitchii(Felt and Young) Culex (Culex) tarsalis Coquillett Aedes (Ochlerotatus) flavescens (Müller) Culex (Neoculex) territans Walker Aedes (Ochlerotatus) hexodontus Dyar Culiseta (Culiseta) alaskaensis (Ludlow) Aedes (Ochlerotatus) impiger (Walker) Culiseta (Culiseta) impatiens (Walker) Aedes (Ochlerotatus) implicatus Vockeroth Culiseta (Culiseta) incidens (Thomson) Aedes (Ochlerotatus) intrudens Dyar Culiseta (Culiseta) inornata (Williston) Aedes (Ochlerotatus) mercurator Dyar Culiseta (Culicella) morsitans (Theobald)

General Tips for Mosquito Identification • Watch out for missing scales or setae by checking for empty pits where they should be. • Northern specimens seem to have reduced abundance of pale scales, so check for these very carefully in steps that use them. • Take care when collecting specimens to keep them as undamaged as possible. The best specimens are adults reared directly from pupae. • Characteristics are in hierarchical order of reliability.

doi:10.3752/cjai.2021.43 2 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Anatomy: Lateral View of Head

Male

Female

Note: for a more detailed overview of anatomy, see Wood et al. (1979)

doi:10.3752/cjai.2021.43 3 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Anatomy: Lateral View of Thorax

Note: the hypostigmal area, postspiracular area, and Note: for a more detailed overview of subspiracular area comprise the anepisternum. anatomy, see Wood et al., (1979)

doi:10.3752/cjai.2021.43 4 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Anatomy: Dorsal View of Thorax

Note: for a more detailed overview of anatomy, see Wood et al. (1979)

doi:10.3752/cjai.2021.43 5 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Anatomy: Dorsal View of Wing

Wing Vein Notation A = anal M = media C = costa R = radial CuA = anterior branch of the cubitus Rs = radial sector CuP = posterior branch of the cubitus Sc = subcosta

Note: for a more detailed overview of anatomy, see Wood et al. (1979)

doi:10.3752/cjai.2021.43 6 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Anatomy: Lateral View of Abdomen

Note: for a more detailed overview of anatomy, see Wood et al. (1979)

doi:10.3752/cjai.2021.43 7 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Anatomy: Lateral View of Leg

Note: for a more detailed overview of anatomy, see Wood et al. (1979)

doi:10.3752/cjai.2021.43 8 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Key to Genera of Adult Female Mosquitoes

Fig 1. Rounded scutellum. Fig 2. Tri-lobed scutellum. (E.g. Anopheles) (E.g. Aedes, Culex, Culiseta)

1. Scutellum rounded (Fig. 1), palps of female about as long as proboscis…………………………………………….……...... Anopheles

1’ Scutellum tri-lobed (Fig. 2), palps of female much shorter than proboscis………………………………………...... 2

doi:10.3752/cjai.2021.43 9 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 3. Postspiracular setae present. Fig 4. Abdominal shapes.

2(1) Postspiracular setae present (Fig. 3), abdomen wide at mid-length, tapering towards the tip (Fig. 4)………………………………..…... Aedes

2’ Postspiracular setae absent, abdomen uniformly wide with blunt tip (Fig. 4) ……………………………………………………………………… 3

doi:10.3752/cjai.2021.43 10 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 5. Prespiracular setae absent. Fig 6. Prespiracular setae present.

3(2) Prespiracular setae present (Fig. 5)……………………………..... Culiseta

3’ Prespiracular setae absent (Fig. 6)…………………………….………….. 4

doi:10.3752/cjai.2021.43 11 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 7. Band of pale scales in middle of first tarsomere.

Fig 8. First tarsomere without band of pale scales in middle.

4(3) First tarsomere and hind tibia with a band of pale scales at middle; wing scales broad and a mix of dark and pale (Fig. 7)………….. Coquillettidia

4’ First tarsomere and hind tibia without a band of pale scales at middle; wing scales narrow and dark (Fig. 8)………………………….….…. Culex

doi:10.3752/cjai.2021.43 12 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Key to Adult Females of the Genus Anopheles

1. Fringe wing scales between apices of R1 and R4+5 bronze or cream- coloured, remaining wing scales dark and aggregated into patches (Fig 9) …………………………………………………………… Anopheles earlei

Fig 9. Wing of An. earlei.

doi:10.3752/cjai.2021.43 13 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Key to Adult Females of the Genus Aedes

1. Tarsomeres with basal or apical bands of pale scales…………………………………………………………………………. 2

1’ Tarsomeres without bands of pale scales…………………..…………………………………………………… 13

Fig 10. Pale scales basal on tarsomeres. Fig 11. Pale scales basal and apical on tarsomeres.

2(1) Tarsomeres with bands of pale scales at base only (Fig. 10) ………….. 3

2’ Tarsomeres with basal and apical band of pale scales (Fig. 11) …….. 12

doi:10.3752/cjai.2021.43 14 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

3(2) Pale bands of hind tarsomeres narrow, occupying 1/5 or less of the length of segment two……………………………………………..… vexans

3’ Pale basal band of hind tarsomere two more than 1/4 the length of the segment…………..……………………………………………………….…. 4

4(3) Abdominal tergites almost completely covered in yellowish scales or with a median longitudinal paler stripe (Fig. 12)……………………..….. 5

4’ Abdominal tergites with pale scales in basal bands only (Fig. 13) …………..…………………………………………………………….……… 6

Fig 12. Aedes nigromaculis (top) and flavescens (bottom). Fig 13. Pale scales in basal bands.

doi:10.3752/cjai.2021.43 15 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

5(4) Abdominal tergites almost completely covered in yellowish scales; proboscis dark-scaled with scattered pale scales…...…..…… flavescens

5’ Abdominal tergites with paler median longitudinal stripe; proboscis with distinct band of pale scales at mid length….…….………… nigromaculis*

6(4) Claws of fore and mid tarsi strongly and abruptly bent, running nearly parallel to subbasal tooth (Fig. 14) …………………………… excrucians

6’ Claws of fore tarsi evenly curved and not nearly parallel to subbasal tooth (Fig. 15)…..……………………………………………………………. 7

Fig 14. Claws abruptly bent. Fig 15.Claws evenly curved.

doi:10.3752/cjai.2021.43 16 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 16.Lower mesepimeral setae present and mesomeron with scales. Fig 17. Lower mesepimeral setae absent and mesomeron without scales. 7(6) Lower mesepimeral setae present; mesomeron with scales on posterodorsal corner (Fig. 16)…………………………………..………… 8

7’ Lower mesepimeral setae absent; mesomeron bare (Fig. 17) …..……..……………………………………..…………………………..…. 10

doi:10.3752/cjai.2021.43 17 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

8(7) Scales on antennal pedicel numerous, mostly pale; brown-scaled (in some specimens dark brown) median and submedian bands on scutum………..………………..………...... 9 8’ Scales on antennal pedicel few and all or most dark; scutum with reddish brown scales, in some specimens with narrow dorso-central stripe of light scales……………………………………….. euedes (in part)

9(8) Wing veins dark-scaled; third fore-tarsomere with an incomplete basal band of pale scales; scutum with pale yellowish scales laterally……………………………………………………………. mercurator 9’ Wings of most specimens with scattered pale scales intermixed with predominantly dark scales; third fore-tarsomere with complete basal band of pale scales; scutum with pale white scales, often mixed with yellow or light brown scales laterally………………………... fitchii (in part)

doi:10.3752/cjai.2021.43 18 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 18. Blunt subbasal tooth. Fig 19. Narrow subbasal tooth. 10 (7) Foretarsi with claws weakly curved, and with a short, blunt subbasal tooth, 1/5 or less the length of claw (Fig. 18)……………………. riparius

10 Claws of foretarsi moderately curved, subbasal tooth at least 1/4 the length of claw (Fig. 19).………………………………………………….. 11

11(10) Proboscis, cerci, and first tarsomere (in addition to their basal band of pale scales) strewn with mottling of pale scales…...… euedes (in part)

11’ Proboscis, cerci, and first tarsomere (other than basal band of pale scales) without pale scales…………………………………. fitchii (in part)

doi:10.3752/cjai.2021.43 19 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

12(2) Wing veins mostly pale-scaled…...……………………………...... campestris

12’ Wing veins dark-scaled…………………………………….…. canadensis

13(1) Wing veins with pale scales beyond the base…...……………………. 14

13’ Wing veins entirely dark-scaled or with pale scales at base of vein C and occasionally Sc and R…………………………….…………….….. 16

doi:10.3752/cjai.2021.43 20 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

14(13) Wing veins alternating between dark-scaled and pale-scaled with R1, R4+5, and C and Cu dark-scaled…...……………………..……. spencerii

14’ Pale scales scattered over all wing veins………………………….….. 15

15(14) Palps and proboscis completely dark-scaled; lower mesepimeral setae absent…………………………………………………. ventrovittis* (in part)

15’ Palps and proboscis with some pale scales; lower mesepimeral setae present……………………………………………………………. cataphylla

doi:10.3752/cjai.2021.43 21 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 20. Scaled postprocoxal membrane. Fig 21. No scales on postprocoxal membrane. 16(13) Postprocoxal membrane with patch of scales (Fig. 20)……………... 17

16’ Postprocoxal membrane without patch of scales (Fig. 21)………….. 25

doi:10.3752/cjai.2021.43 22 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

17(16) Numerous setae arising from postpronotum and scutum, long and scattered in distribution giving thorax a hairy appearance……….….. 18

17’ Postpronotum with setae restricted to one or two rows on posterior margin and scutum with normal, sparse setae………………………... 19

18(17) Hind tarsal claw sharply bent beyond, and nearly parallel to, its subbasal tooth (Fig. 22)….……………….…………………….….. impiger

18’ Hind tarsal claw weakly bent beyond, and not parallel to, its subbasal tooth (Fig. 23)……………………………………………………..... nigripes

Fig 22. Claw sharply bent. Fig 23. Claw not sharply bent.

doi:10.3752/cjai.2021.43 23 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 24. Without scales in anterodorsal corner of katepisternum. Fig 25. Scales in anterodorsal corner of katepisternum. 19(17) Katepisternum without scales in anterodorsal corner, and bottom 1/5 of mesepimeron also without scales (Fig. 24)…….……………………… 20

19’ Katepisternum with scales extending to anterodorsal corner and mesepimeron completely covered in scales (Fig. 25)………………... 21

doi:10.3752/cjai.2021.43 24 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 26. Presence of lower mesepimeral setae. Fig 27. Absence of lower mesepimeral setae.

20(19) Lower mesepimeral setae present (Fig. 26)………………….. implicatus

20’ Lower mesepimeral setae absent (Fig. 27)……….. ventrovittis* (in part)

doi:10.3752/cjai.2021.43 25 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 28. Presence of scales in hypostigmal area. Fig 29. Absence of scales in hypostigmal area.

21(19) Hypostigmal area with scales (Fig. 28).…………………….. provocans*

21’ Hypostigmal area without scales (Fig. 29)…………………………...... 22

doi:10.3752/cjai.2021.43 26 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

22(21) Scutum with narrow, pale-scaled median band separating dark-brown scaled submedian bands……….………………………….………. pionips

22’ Median and submedian bands of scutum dark-scaled and fused, forming a single, comprehensive middorsal stripe, OR lacking dark submedian stripes………………………………………………………... 23

Fig 30. Anterior view of thorax with Fig 31. Anterior view of thorax with probasisternum covered with scales. probasisternum not covered with scales.

23(22) Probasisternum wholly covered with scales (Fig. 30)…...… hexodontus

23’ Probasisternum bare or with scattered pale scales on dorsal half (Fig. 31) ………...... 24

doi:10.3752/cjai.2021.43 27 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

24(23) Median and submedian bands of scutum appearing as single broad middorsal stripe of dark brown scales; base of wing vein C with pale scales in some specimens…………………….………….…...…. punctor 24’ Scales of scutum uniformly medium brown (narrow scales may cause submedian bands to appear darker); base of wing vein C invariable dark scaled; southwest Yukon...... aboriginis*

Fig 32. Ventral anepisternum un-scaled. Fig 33. Ventral anepisternum scaled. 25(16) Ventral margin of anepisternum without scales (Fig. 32); patch of black scales behind each eye..…..………………………………...…… cinereus 25’ Ventral margin of anepisternum with numerous pale scales (Fig. 33); no dark-scaled patches behind eyes...... 26

doi:10.3752/cjai.2021.43 28 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 34. Abdominal tergites with pale-scaled basolateral patches and narrow basal bands on apical segments.

26(25) Abdominal tergites with basal bands of pale scales………………….. 27

26’ Abdominal tergites without basal bands but with pale-scaled basolateral patches (may be joined by narrow basal bands on apical segments) (Fig. 34)………………………………………………………. 31

doi:10.3752/cjai.2021.43 29 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 35. Scales to anterodorsal corner of katepisternum. Fig 36. Anterodorsal corner of katepisternum un-scaled 27(26) Scales of katepisternum extending to the anterodorsal corner (Fig. 35) …………………………………………………………………….………. 28

27’ Scales of katepisternum not extending to the anterodorsal corner (Fig. 36)………………………………………………………………….……… 30

doi:10.3752/cjai.2021.43 30 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 37. Lower mesepimeral setae absent. Fig 38. Lower mesepimeral setae present. 28(27) Scales of median and submedian scutal bands uniformly reddish- brown; dorsal half of postpronotum with reddish-brown scales; lower mesepimeral setae absent (Fig. 37); ventral 1/4 of mesepimeron without scales………….…………………………………………… sticticus 28’ Scales of submedian scutal band brown and median band pale; dorsal half of postpronotum with yellowish-brown scales; lower mesepimeral setae present (Fig. 38); ventral 1/4 of mesepimeron scaled………… 29

doi:10.3752/cjai.2021.43 31 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 39. Long and narrow subbasal tooth. Fig 40. Short and thick subbasal tooth. 29(28) Subbasal tooth long and narrow (Fig. 39)……………………. communis

29’ Subbasal tooth short and thickened at base (Fig. 40)….. churchillensis*

30(27) Scutum with scales a uniformly bronzy or yellowish-brown; vertex scales yellow……………………………………………………… intrudens

30’ Scutum with submedian bands of dark brown scales separated by pale scales of median band; vertex scales both light and dark…….. pullatus

doi:10.3752/cjai.2021.43 32 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Fig 41. Ae. diantaeus claw and metameron. Fig 42. Ae. decticus claw and metameron. 31(26) Vertex scales homogenously yellowish; patch of scales on metameron, claw of fore tarsi long, slender, and less curved (Fig. 41)…... diantaeus

31’ Vertex with dark scales, in two sub-median patches, mixed into pale scales; metameron un-scaled; claw of fore tarsi heavily curved (Fig. 42)…………………………………………………………………… decticus

doi:10.3752/cjai.2021.43 33 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Key to Adult Females of the Genus Coquillettidia

1. Wing scales broad; proboscis with a band of pale scales at mid-length; hind tibia usually with a band of pale scales at mid-length …………..…………..…………………………….. Coquillettidia perturbans

Fig 43. Broad wing scales of Cq. Fig 44. Generalized narrow wing scales of other perturbans. species.

doi:10.3752/cjai.2021.43 34 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Key to Adult Females of the Genus Culex

Fig 43. Cx. tarsalis proboscis with band of pale scales.

Fig 44. Cx. territans abdominal tergites with apical transverse bands of pale scales. 1. Tarsomeres with basal and apical bands of pale scales; basal transverse bands of pale scales on abdominal tergites; proboscis with band of pale scales at mid-length (Fig. 43)……………………….. tarsalis 1’ Tarsomeres and proboscis unbanded; apical transverse bands of pale scales on abdominal tergites (Fig. 44)…………………...... territans

doi:10.3752/cjai.2021.43 35 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Key to Adult Females of the Genus Culiseta

1. Hind tarsomeres without band of pale scales (can be very narrow in some specimens)……………………………...……………………………. 2

1’ Hind tarsomeres with bands of pale scales on at least some segments, very narrow in some species………………………………………………. 3

2(1) Wings with scattered pale scales; abdominal tergites with scattered pale scales and broad basal bands……………………………… inornata

2’ Wings dark-scaled; abdominal tergites with narrow basal band of pale scales……………………………………………………………... impatiens

doi:10.3752/cjai.2021.43 36 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

3(1) Hind tarsomeres with narrow basal bands about as long as diameter of segment is wide (can be small and difficult to see) …………………… 4

3’ Hind tarsomeres with broad basal bands covering about ¼ of the segment………………………………………………………… alaskaensis

Fig 45. Cs. incidens katepisternum. Fig 45. Cs. morsitans katepisternum. 4(3) Wing scales aggregated into dark patches on veins; anterodorsal corner of katepisternum with scales (Fig. 44)………………….. incidens

4’ Wing scales distributed evenly; anterodorsal corner of katepisternum without scale (Fig. 45)………………….……………………….. morsitans

doi:10.3752/cjai.2021.43 37 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Species Profiles 1983). SSHV has been isolated from this species (McLean et al., 1972). We have only collected it from Anopheles earlei Vargas one location southeast of Watson Lake in the Yukon, in The only anopheline known from the Yukon, this July, and literature records indicate a sparse distribution. species completes only one generation per year in the In Northern British Columbia it is most common early northern climate, rather than two per year in the south in the summer (D.A.H. Peach, personal observation), a (Wood et al., 1979). Adult females overwinter in warm phenology that has also been noted in Southern Ontario areas such under tree bark, in sheds or houses, in (Giordano et al., 2018) and Quebec (Shahhosseini et al., mammal burrows (Belton, 1983), and notoriously even 2020). in beaver lodges (Hudson, 1978). Mammals are the preferred host (Anderson & Galloway, 1988). Eggs are Aedes (Ochlerotatus) cataphylla Dyar laid singly on standing water such as marshes, ponds, This species completes a single generation per year ditches, or other permanent or semi-permanent bodies of (Becker et al., 2010). It overwinters in the egg stage and water with abundant emergent vegetation at the margins is among the earliest species to emerge in the spring, (Wood et al., 1979; Anderson & Galloway, 1988). An. often as soon as the snow melts (West and Black, 1998). earlei are found throughout the Yukon near appropriate Larvae can develop quickly even at low temperatures larval habitat. We have found larvae in late June and (Pritchard and Scholfield, 1983) and are found in a variety early July in southern parts of the Territory, and have of temporary pools but are most common in snow melt even occasionally observed adults day-resting under the pools in grassy areas and forests (Belton, 1983; Becker roof inside outhouses. et al., 2010). Females take blood from mammals and can be very aggressive (Wood et al., 1979; Belton, 1983). It Aedes (Ochlerotatus) campestris Dyar and Knab can be found all over the Yukon in grassland and open A light-coloured grassland species that can reach forest, though it is more numerous in the south. Many prodigious numbers and bite aggressively, this species specimens we have seen appear to have fewer scattered completes only one generation a year in the north (Wood white scales present on the wing beyond the basal patch et al., 1979). Overwintering in the egg stage, the larvae on C than specimens from southern British Columbia. are found in temporary water pools, particularly in grassy areas, and can tolerate alkaline conditions (Wood et al., Aedes (Aedes) cinereus Meigen 1979). The preferred hosts of Ae. campestris are mammals Ae. cinereus overwinters in the egg stage and can (Belton, 1983), and it is one of the most common complete multiple generations per year in southern mosquitoes at livestock facilities in Alberta (Lysyk, Canada and Europe (Wood et al., 1979; Becker et al., 2010). Viruses of the California serogroup have been 2010), although whether this occurs in northern Canada isolated from Ae. campestris in New Mexico (Clark et is unknown. Larvae are found at the edges of permanent al., 1986), and WEEV has been isolated from this species or semi-permanent marshes, bogs, lakes, ditches, or other in areas south of the Yukon (McLintock et al., 1970; water with standing vegetation (Wood et al., 1979; Becker Clark et al., 1986). We have collected adult specimens et al., 2010). In North Carolina adults of this species was from Kluane National Park with orchid pollinia attached associated with forest habitat (Reiskind et al., 2017), and to them, and this has also been observed in other areas it takes blood meals from mammals and birds (Börstler (Hocking et al., 1950). We have also collected specimens et al., 2016; Shepard et al., 2016). This species will bite from other parts of the Yukon, particularly Ibex Valley, readily throughout the day in shaded conditions (Gilardi carrying heavy loads of mites. This species is found and Hilsenhoff, 1992). Ae. cinereus is predominantly an locally in the southern Yukon in or near grassy areas and early summer species in Quebec (Shahhosseini et al., occasionally in other open areas. 2020), and we have collected it in late June and July from the Yukon. Aedes (Ochlerotatus) canadensis (Theobald) This woodland species takes blood primarily from Aedes (Ochlerotatus) communis (de Geer) small mammals, but will also bite birds, amphibians, The Yukon’s most widespread and abundant mosquito and reptiles (Hayes, 1961; Shepard et al., 2016). It has south of the treeline, this forest species (Hocking et al., one, or possibly two, generations a year (Wood et al., 1950) can be found in large numbers in the vicinity of 1979). Winter is spent in the egg stage and hatching after most population centres in the Territory. Winter is spent diapause may be staggered (Wood et al., 1979). Larvae in the egg stage and larvae are found in temporary pools are found in a wide variety of temporary pools, usually of acidic water formed by heavy rainfall or melting snow in wooded areas, including those formed by snowmelt, (Wood et al., 1979; Becker et al., 2010). Ae. communis is flooding, or intense rainfall (Wood et al., 1979; Belton, an aggressive biter (Belton, 1983) that emerges early in

doi:10.3752/cjai.2021.43 38 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

Aedes (Ochlerotatus) excrucians (Walker) the summer (Shahhosseini et al., 2020) and takes blood from mammals (Börstler et al., 2016). It is the north’s Ae. excrucians overwinters in the egg stage and primary natural vector of SSHV (McLean & Lester, completes one generation per year (Wood et al., 1979). 1984), and is a predominant species in mosquito pools Larvae are found in a wide variety of temporary pools that test positive for Francisella tularensis in Alaska and semi-permanent marshes, though there is likely a (Triebenbach et al., 2010). high-degree of flexibility in larval habitat (Wood et al., 1979; Belton, 1983). While Ae. excrucians larvae are Aedes (Ochlerotatus) decticus Howard, Dyar, and Knab common, they are usually not the dominant species in a This is a forest species (Gjullin et al., 1961) that given breeding site (Gilardi and Hilsenhoff, 1992). The completes one generation per year and overwinters in adults are fiercely aggressive biters (Becker et al., 2010) the egg stage (Gilardi & Hilsenhoff, 1992). Larvae are that tend to be found in the early summer (Shahhosseini found in bogs or swamps, particularly sphagnum bogs et al., 2020), and are frequently the predominant species (Gjullin et al., 1961; Gilardi & Hilsenhoff, 1992; Peach in mosquito pools that test positive for Francisella and Poirier, 2020) and in northern Quebec are associated tularensis in Alaska (Triebenbach et al. 2010). In the with bog pools below adjacent ridges dominated by Carex Yukon adults are found in low numbers in most habitats limosa (Maire, 1982). Ae. dectictus is widely distributed other than tundra, similar to other areas (Wood et al., but fairly rare (Wood et al., 1979). In the Yukon we have 1979). Wood et al. (1979) noted that specimens from the collected it from just outside of Whitehorse and from Yukon and other northern areas seem to appear larger and Watson Lake, but have also found it in nearby Northern darker than those from the south, and our observations British Columbia (Peach and Poirier 2020). Ae. decticus corroborate this. will take blood from humans (Barr & Balduf, 1965), but little is known about its feeding habits or its biology in Aedes (Ochlerotatus) fitchii(Felt and Young) general. A mosquito primarily of open woodland areas, this Aedes (Ocherlotatus) diantaeus Howard, Dyar, and species is very similar to Ae. excrucians in appearance Knab and the larvae of these two species often co-occur. Ae. fitchiiand Ae. excrucians are similar in appearance and This species overwinters in the egg stage and habitats and the two are easily confused, though Ae. completes one generation per year (Becker et al., 2010). fitchiiadults tend to emerge later than Ae. excrucians Larvae are most often found in boggy habitat or similar (Gilardi and Hilsenhoff, 1992). Ae. fitchii completes one conditions and in Wisconsin are affiliated with sphagnum generation per year and overwinters in the egg stage (Gilardi and Hilsenhoff, 1992). Ae. diantaeus larvae are (Wood et al., 1979). Larvae are most often found in commonly associated with the larvae of other species, temporary pools of water such as those left behind by particularly those of Ae. communis (Wood et al., 1979). heavy rains or melting snow (Belton, 1983). It has been Ae. diantaeus larvae suspend themselves vertically on the found throughout the Yukon but is usually present in debris at the bottom of a pool, resting on the tips of their low numbers, though it can be an aggressive biter. antennae, and may rely upon the organic matter thrown up by the feeding of other larvae as a food source (Wood Aedes (Ochlerotatus) flavescens (Müller) et al., 1979). Most adult females probably take blood from mammals (Jaenson, 1985). We have collected this A large species found in grassland or prairie-like species from Watson Lake and from the southern shore habitat, this is the largest Aedes species in Canada (Wood of Kluane Lake. et al., 1979). Ae. flavescens overwinters in the egg stage and produces only one generation per year (Wood et al., Aedes (Ochlerotatus) euedes Howard, Dyar, and Knab 1979). Adult females take blood from mammals and birds Ae. euedes overwinters in the egg stage and completes (Wang et al., 2012), including livestock (Hudson, 1983) one generation per year (Wood et al., 1979). It will take and can be aggressive in their biting (Belton, 1983). blood from humans (Belton, 1983) and larvae tend to be Larvae can tolerate a wide range of salinity (Becker et al., found in association with large open marshes or nearby 2010), are found in a variety of temporary pools in grassy woodlands (Gilardi and Hilsenhoff, 1992). Ae. euedes habitat, and are among the latest species to develop has been recorded only from the southeastern Yukon (Wood et al., 1979). We have not collected it from the (Peach and Poirier, 2020), but there are records of this Yukon and it may be present only in very low numbers. species from the Arctic coast of the Northwest Territories (Wood et al., 1979) and as such it may occur throughout Aedes (Ochlerotatus) hexodontus Dyar the Yukon. This cold-adapted species completes one generation per year and overwinters in the egg stage (Wood et al.,

doi:10.3752/cjai.2021.43 39 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

1979), hatching when water is just above 0 oC (Becker year and overwinters in the egg stage (Wood et al., et al., 2010). Larvae are found in a variety of temporary 1979). Larvae are fairly ubiquitous and are found in a freshwater habitats but are particularly abundant in pools wide variety of temporary pools such as those left by along the margins of rivers in cold areas (West and Black, melting snow (Denke et al., 1996). Ae. implicatus is 1998) as well as tundra and into nearby forested areas an early season mosquito that emerges as adults before where they will fly and bite even in strong winds (Wood most other species (Gjullin et al., 1961). Adults can be et al., 1979). Further south Ae. hexodontus becomes vigorous biters (Belton, 1983) and can be very annoying abundant in the alpine and sub-alpine (Wood et al., when present in large numbers. SSHV has been isolated 1979; Belton, 1983). In northern Quebec this species from larvae reared to adulthood (McLintock et al., 1976), was associated with bog pools below adjacent ridges possibly implicating this species as an overwintering dominated by Carex limosa (Maire, 1982). Wood et al. virus reservoir. (1979) believed that “This species, probably more than any other, is responsible for the formidable reputation that Aedes (Ochlerotatus) intrudens Dyar the arctic has for mosquitoes. It attains extraordinarily This species overwinters in the egg stage and has high populations in the northern fringes of the boreal one generation per year in northern areas (Becker et al., forest and adjacent tundra in Canada, Alaska, and Eurasia, 2010). Eggs are deposited on soil in depressions that where permafrost and poor drainage combine with a turn into temporary pools of snow meltwater (Wood et relatively warm summer and abundant algal growth to al., 1979; Schӓfer and Lunstrӧm, 2001). Ae. intrudens provide almost unlimited opportunities for mosquito feeds on mammals and is a persistent biter of humans breeding”. Ae. hexodontus may serve as a mammalian (Wood et al., 1979), though at least in southern Canada vector of SSHV and NORV in the Yukon (McLean & it is generally only present early in the season (Trueman Lester, 1984). In Russia it has been observed feeding and McIver, 1986). Named intrudens for its aptitude at on haemolymph from eclosing reindeer nose botflies, entering human buildings, this species is generally found Cephenemyia trompe (Poliakova and Gomojunova, south of the treeline (Wood et al., 1979) and it prefers 1973). forested habitats (Schӓfer and Lunstrӧm, 2001). It is an aggressive biter, though it is considered a short-lived Aedes (Ochlerotatus) impiger (Walker) species (Wood et al., 1979) and we have only encountered A cold-adapted species found throughout the arctic a few of them in the Yukon. tundra, subarctic, and in alpine areas, adults are small and fast fliers able to fly in windy conditions (Wood Aedes (Ochlerotatus) mercurator Dyar et al., 1979). Ae. impiger overwinters in the egg stage This is an uncommon mosquito that was confused and completes one generation per year (Becker et al., with Ae. stimulans in the past, and as such there are many 2010). It undergoes an extended diapause, with eggs gaps in our knowledge of it (Wood et al., 1979). It was from Russian populations requiring at least 180 days first described from specimens collected at Dawson, below -3 oC before larvae, which develop rapidly, will Yukon Territory (Dyar, 1920). Larvae are found at the emerge (Tamarina and Aleksandrova, 1984). Adults open, vegetated edges of semipermanent pools (Wood bite throughout the extended northern day and feed et al., 1979). Belton (1983) found it in dry forest and on a variety of animals (Tamarina and Aleksandrova, parkland in British Columbia, similar to the conditions 1984), but notably have also been observed feeding it has been found from in northern Russia (Panyukova, on haemolymph of eclosing reindeer nose botflies, 2019), and the specimens we have collected in the Yukon Cephenemyia trompe (Poliakova and Gomojunova, came from a dry forest area. On the opposite side of the 1973). Whether or not similar behaviour occurs in the country, on Prince Edward Island, it has been reported Yukon is unknown. If an adult female consumes nectar from similar habitat (Giberson et al., 2007). she can develop a small number of eggs without taking a blood meal (Wood et al 1979). This species is a pollinator Aedes (Ochlerotatus) nigripes (Zetterstedt) of Dryas integrifolia in the Canadian high arctic (Kevan, The most abundant and widespread arctic mosquito 1972) and may play such a role in parts of the Yukon (Müllerová et al., 2018), Ae. nigripes is found in tundra as well. Unidentified Orthobunyavirus DNA was found north of the treeline or in alpine areas as far south as in Ae. impiger collected at Thule air base in Greenland, northern British Columbia (Wood et al., 1979) and is where breeding conditions and access to blood allowed one of the first species to appear (Lewis and Webber, this species to reach pest status (Reeves et al., 2013). 1985). This species overwinters in the egg stage and completes one generation per year (Becker et al., 2010). Aedes (Ochlerotatus) implicatus Vockeroth Ae. nigripes takes blood meals from mammals and birds A forest species that completes one generation per (Wood et al., 1979) but can also develop a small number

doi:10.3752/cjai.2021.43 40 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

of eggs without taking a blood meal by obtaining energy right conditions in Britain (Packer and Corbet, 1989). from floral nectar (Wood et al., 1979). In the Yukon Ae. Eggs are deposited in bands (Fallis and Snow, 1983) nigripes is a secondary vector of SSHV (McLean & above the prevailing water level in in depressions that Lester, 1984). This species is a pollinator of the white hold temporary pools, such as those formed by melting mountain-avens, Dryas integrifolia, in the Canadian high snow, in boggy forest areas (Becker et al., 2010). Adult arctic (Kevan, 1972) and may play a similar role in the females will take blood from birds and mammals and Yukon. When the right environmental conditions are met have been found with up to 170 eggs (Hocking et al., Ae. nigripes numbers and the timing of their emergence 1950). can induce egg-loss in arctic-nesting birds in other areas of northern Canada (Gaston et al., 2002). Aedes (Ochlerotatus) riparius Dyar and Knab This species spends the winter in the egg stage Aedes (Ochlerotatus) pionips Dyar and is thought to complete only one generation per The most common species encountered by Nelson year (Becker et al., 2010). Aedes riparius is usually (1977), this species is closely associated with Aedes uncommon or rare within most of its range (Wood et al., communis, though it develops more slowly (Wood et 1979), though it is most common in grassland and open al., 1979). Ae. pionips completes one generation per parkland habitat (Belton, 1983). Larvae can be found in year, deposits its eggs on soil, and overwinters in the tree-shaded pools or marshes in suitable habitat (Gilardi egg stage (Wood et al., 1979; Schӓfer and Lunstrӧm, and Hilsenhoff, 1992), and also occasionally in peat bogs 2001). Larvae are found in a wide variety of habitats, (Becker et al., 2010). In northern Quebec Ae. riparius and are a pioneer of new habitats (Jenkins, 1948), but larvae are associated with bog pools below adjacent they are most common in pools of water left behind by ridges dominated by Carex rostrata (Maire, 1982). Ae. melting snow in boggy forests (Becker et al., 2010) or riparius has only been reported from the southern Yukon other timbered areas (Denke et al., 1996), and adults are and in low numbers, though it has also been rarely found common in most lowland areas of the Yukon below the in central Alaska, in the vicinity of black spruce muskeg treeline. Mammals are the preferred source of blood for (Gjullin et al., 1961). We have only collected it from two Ae. pionips (Schӓfer and Lunstrӧm, 2001). locations in the Yukon, both near Watson Lake, and both locations were dry open parkland habitat. Ae. riparius Aedes (Ochlerotatus) pullatus (Coquillett) takes blood from mammals (Schӓfer and Lunstrӧm, This species has a disjunct range, with a population 2001) and we have observed this to include humans. in northern Quebec and another in the Yukon and British Columbia, possibly due to incomplete dispersal from past Aedes (Ochlerotatus) spencerii ssp. spencerii (Theo- glacial refugia (Wood et al., 1979). Ae. pullatus prefers bald) forested habitat, completes one generation per year, An inhabitant of grassland areas with characteristic overwinters in the egg stage, and is one of the last species alternating dark- and pale-scaled wing veins (Wood to emerge in the spring (Wood et al., 1979; Schӓfer and et al., 1979), in the Yukon Ae. spencerii is known only Lunstrӧm, 2001). It deposits eggs on the soil in and from the vicinity of grasslands in the southwest of the above depression that fill with snowmelt water or in other Territory (Peach, 2017), though low numbers may be small pools with clear water (Jenkins, 1948; Schӓfer and found in nearby woodlands. In Wyoming it has been Lunstrӧm, 2001), and we have observed its larvae in found from low elevations up to 3000 m (Denke et al., mossy floodwater and snowmelt pools often surrounded 1996). Adult females will take blood from birds and by Salix spp. in alpine and subalpine areas of the Yukon mammals (Rempel et al., 1946). Larvae are found in and British Columbia. In the north Ae. pullatus can be temporary pools of floodwater, rainwater, or meltwater, found at all elevations, though they are more common at in grassy areas or pasture, and can develop rapidly at low higher altitudes (Jenkins, 1948). temperatures, allowing for emergence in more southern locations as early as April or as late as September with Aedes (Ochlerotatus) punctor (Kirby) multiple generations per season possible under the right A woodland species (Hocking et al., 1950) that is one environmental conditions (Philip, 1943; Wood et al., of the most common mosquitoes in the boreal forest in 1979). both Canada (Wood et al., 1979) and Russia (Panyukova, 2019), Aedes punctor is often among the first species to Aedes (Ochlerotatus) sticticus (Meigen) emerge in the spring in Ontario (Trueman and McIver, A floodwater species associated with bottomlands of 1986), and is reported to be associated with sphagnum river valleys, the eggs of Aedes sticticus are deposited in (Gilardi and Hilsenhoff, 1992). It has been observed to areas prone to flooding and can remain viable for several complete more than one generation per season under the years and, therefore, adults may be absent for several

doi:10.3752/cjai.2021.43 41 Canadian Journal of Arthropod Identification No. 43 (February, 2021) PEACH et al.

seasons if conditions are unfavourable before emerging mud at the bottom of ponds, marshes, and other permanent again when better conditions present themselves (Wood shallow waterbodies, where they also overwinter (Wood et al., 1979). Eggs can hatch in floodwater that is below et al., 1979). Cq. perturbans larvae are associated with 8 oC (Becker et al., 2010), and with the right conditions sites that have at least 0.5 m of water depth, lower several generations can occur each year (Becker et al., dissolved oxygen content, and a mean detritus layer of 2010). Adults can disperse, with the wind, up to almost greater than 10 cm in Minnesota (Batzer and Sjorgen, 10 km from their larval habitats (Brust, 1980) and will 1986). While they are associated with cattails (Typha invade houses (Hearle, 1926). This species seems to be spp.) elsewhere (Batzer and Sjorgen, 1986) these were rare in the Yukon, with our only two collection records not observed where Cq. perturbans have been collected from northwest of the Donjek River (Peach, 2017) and in the Yukon (Peach and Poirier, 2020) and other larval from near Squanga Lake, and what populations exist host plants might be used. Cq. perturbans is particularly may be restricted to flat river floodplains, intermittently active just after dusk (Anderson et al., 2007). Females emerging only in particularly warm summers. take blood meals from humans and other mammals, as well as birds (Wood et al., 1979). Cq. perturbans is a Aedes (Aedimorphus) vexans (Meigen) vector of WNV (Turrell et al., 2005) and in eastern North Multiple generations of Aedes vexans can occur each America is a vector of EEEV (Cupp et al., 2003). year depending on temperature and rainwater runoff (Wood et al., 1979). This species overwinters in the egg Culex (Culex) tarsalis Coquillett stage and is highly adapted to ephemeral water conditions A dark culicine possessing a conspicuous band of (Kroeger et al., 2014), their eggs hatching with sufficient white scales at mid-length of the proboscis, as well as flooding and warm temperatures (Wood et al., 1979). white tarsal bands (Wood et al., 1979). Eggs are deposited Eggs laid on soil in areas prone to flooding by the adults as a raft on the water’s surface and larvae are often found of this first spring generation can, after 3-5 days of dry in standing water in or near grassy areas, as well as in weather and subsequent re-flooding, emerge as adults flooded meadows or fields. While thus far it is known in in as little as 120 hours in the right conditions (Wood the Yukon from only a single location in the southwest et al., 1979). Temporary aquatic habitats such as flood (Peach, 2018), Cx. tarsalis has also been found in the water, irrigated pasture, and woodland pools all provide Northwest Territories (Wood et al., 1979) and should be excellent habitat for Ae. vexans larvae (Belton, 1983). watched for in collections. Adult females of Cx. tarsalis Female Aedes vexans can fly up to 17 km and can lay up overwinter in warm, dry areas such as under rock piles, to 120 eggs per batch (Briegel et al., 2001). in mammal burrows, or in human structures (Belton, Females have been found naturally infected with 1983). Blood meals are taken from birds and mammals WEEV in western Canada (McLintock et al., 1970) and (Becker et al., 2010), allowing Cx. tarsalis to function as the northwestern United States (Gjullin & Eddy, 1972). the primary vector of WNV and WEEV in Western North This species is a bridge vector of WNV in the US and America, among other pathogens (Goddard et al., 2002; southern Canada (Turell et al., 2005; Giordano et al., Turell et al., 2005; Chen et al., 2012). WNV is endemic 2017), and field collected specimens in North Dakota in British Columbia (Roth et al., 2010) and the Prairie yielded isolates of WNV, SSHV, and several other provinces (Chen et al., 2012), and migratory birds with viruses (Anderson et al., 2015). Aedes vexans feeds on WNV antibodies have been detected in Alaska (Pederson mammals and can be a terrible pest in southern Canada, et al., 2016). WNV transmission requires 109 degree with populations reaching astronomical numbers when days and cannot develop in Cx. tarsalis at temperatures appropriate conditions are met (Hearle, 1926). We have below 14.3 oC (Reisen et al., 2006), and although only collected this species twice, both in the south of the endemic transmission has not been documented in the territory, and it seems to be very rare. Yukon some models predict the possibility of WNV risk in the extreme southern Yukon during the second half of Coquillettidia (Coquillettidia) perturbans (Walker) the 21st century (Harrigan et al., 2014). Cx. tarsalis has Coquillettidia perturbans is an aggressive biter known been observed nectar feeding on several Asteraceae and only from the southeast Yukon (Peach and Poirier, 2020). may pollinate these flows (Peach and Gries, 2016; Philip, This species has prominent tarsal bands and wings which 1943). look “dusty” due to the presence of intermixed dark and pale scales (Wood et al., 1979; Belton, 1983; Thielman Culex (Neoculex) territans Walker and Hunter, 2007). Cq. perturbans has a very unique life Cx. territans overwinters in the adult stage and history - the larvae possess a modified siphon by which produces one g